All the talk had been of whether Gerrard could finish his Liverpool career by lifting the FA Cup next month on his birthday in his final game before joining LA Galaxy, but there will no fairytale end for the long-serving captain.
Philippe Coutinho put the Merseyside club in front after half an hour to put them on course for a clash against Arsenal on May 30, but Villa fought back to reach their first FA Cup final for 15 years.
Christian Benteke equalised shortly after Coutinho's strike, continuing his incredible run of form with a ninth goal in seven matches.
Tim Sherwood's men continued to impress after the break and took the lead through a Delph goal with 54 minutes on the clock, forcing Liverpool to play more expansively.
Mario Balotelli had a late goal wrongly ruled out for offside and Villa held on to keep their dreams of winning the FA Cup for the first time since 1957 well and truly alive.
Gerrard and Martin Skrtel both slotted back into the Liverpool team following their respective bans, but the talismanic captain had little effect during the early exchanges as Villa began brightly.
Villa youngster Jack Grealish looked particularly threatening, but it was Charles N'Zogbia who had the first attempt at goal with a 25-yard drive which was tipped over the crossbar by Simon Mignolet in the 12th minute.
Despite their superiority, Villa struggled to craft goal-scoring opportunities and Liverpool capitalised on hesitant defending to take a 30th-minute lead.
Jores Okore - on for Nathan Baker after he took a blow to the head - and Delph both failed to clear and, Coutinho burst into the penalty area and coolly slotted past Shay Given after racing on to Raheem Sterling's through ball.
Their joy was short-lived, however, as Villa deservedly levelled only six minutes later.
A fine move down the left resulted in Grealish releasing Delph in the area and his cut-back was dispatched beyond Mignolet by the lurking Benteke, his fifth goal in seven games against the Merseyside club.
Rodgers introduced Balotelli for the anonymous Lazar Markovic at half-time, but that switch changed little with regards to Villa's control and Sherwood's side soon had a well-earned lead.
The impressive Grealish produced a clever reverse pass into the area for Delph and the England international jinked past Dejan Lovren, before sliding past Mignolet.
Falling behind forced Liverpool's hand and they began to open up, finding themselves exposed on the break on a couple of occasions.
However, Villa were unable to punish them again and Liverpool piled the pressure on towards the end, Gerrard – who was far from his best – having a header cleared off the line by Kieran Richardson with four minutes to go.
There was further frustration for Liverpool as Balotelli incorrectly had an 88th-minute strike disallowed for offside and that proved to be a costly decision, as Villa held on to book another trip to Wembley.
